The present specification relates to displays. More particularly, the present specification relates to head up displays (HUDs) including stow mechanisms.
Conventional HUDs are generally large, expensive and difficult to fit into small airplanes. Often, conventional HUDs rely on large lenses to form adequate field of view and viewing eye box. Compact HUDs are needed for small business jets and other aircraft where space is constrained in the cockpit.
Substrate guided HUDs have been proposed which use wave guide technology with diffraction gratings to preserve eye box size while reducing lens size. However, even though substrate guided HUDs are smaller than conventional HUDs, they are still difficult to stow in small cockpits. Conventional stow paths generally only rotate through a single axis and swing through areas for the pilot's head or stop too close to the pilot's head. Further, conventional stow mechanisms are expensive and bulky.
Therefore, there is a need for a compact HUD for small aircraft, such as small business jets. Further, there is a need for a compact HUD which reduces stowage and break-away issues. Yet further, there is a need for a HUD that allows easy ingress/egress. Yet further still, there is also a need for a lightweight, lower cost, smaller sized stow mechanism of a HUD. Yet further, there is a need for a stow mechanism and method optimized for use with a substrate waveguide HUD.